Joseph J. Sitt is an American real estate investor, founder of the retail chain Ashley Stewart, and founder of global real estate company Thor Equities.

Thor Equities is a real estate development, leasing and management firm, with headquarters in New York City, London and Mexico City. Thor Equities owns property in the United States, Canada, Europe, Russia, India and Latin America, including London's historic Burlington Arcade and the Palmer House Hilton. In New York City, Thor owns retail, office and residential properties on Fifth Avenue and Madison Avenue as well as in SoHo, Flatiron, the Meatpacking District, and Brooklyn including Coney Island. Thor also has investments in major U.S. cities including San Francisco's Union Square; Georgetown in Washington, D.C.; Robertson Boulevard in West Hollywood; Collins Avenue; Lincoln Road; Wynwood and the Design District in Miami. Thor offers investment vehicles for institutional investors through its Thor Urban Property Funds. Thor Equities also has several subsidiary companies including retail advisory and tenant representation firm Thor Retail Advisors.